aac.c

   1 /*
   2  * Copyright 2006 dnk <dnk@bjum.net>
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License as
   6  * published by the Free Software Foundation; either version 2 of the
   7  * License, or (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  17  * 02111-1307, USA.
  18  */
  19
  20 #include "ip.h"
  21 #include "xmalloc.h"
  22 #include "debug.h"
  23 #include "id3.h"
  24 #include "comment.h"
  25 #include "read_wrapper.h"
  26
  27 #include <faad.h>
  28
  29 #include <errno.h>
  30 #include <string.h>
  31 #include <sys/types.h>
  32 #include <unistd.h>
  33 #include <fcntl.h>
  34
  35 /* FAAD_MIN_STREAMSIZE == 768, 6 == # of channels */
  36 #define BUFFER_SIZE     (FAAD_MIN_STREAMSIZE * 6 * 4)
  37
  38 struct aac_private {
  39         char rbuf[BUFFER_SIZE];
  40         int rbuf_len;
  41         int rbuf_pos;
  42
  43         unsigned char channels;
  44         unsigned long sample_rate;
  45
  46         char *overflow_buf;
  47         int overflow_buf_len;
  48
  49         faacDecHandle decoder;  /* typedef void * */
  50 };
  51
  52 static inline int buffer_length(const struct input_plugin_data *ip_data)
  53 {
  54         struct aac_private *priv = ip_data->private;
  55
  56         return priv->rbuf_len - priv->rbuf_pos;
  57 }
  58
  59 static inline void *buffer_data(const struct input_plugin_data *ip_data)
  60 {
  61         struct aac_private *priv = ip_data->private;
  62
  63         return priv->rbuf + priv->rbuf_pos;
  64 }
  65
  66 static int buffer_fill(struct input_plugin_data *ip_data)
  67 {
  68         struct aac_private *priv = ip_data->private;
  69         int32_t n;
  70
  71         if (priv->rbuf_pos > 0) {
  72                 priv->rbuf_len = buffer_length(ip_data);
  73                 memmove(priv->rbuf, priv->rbuf + priv->rbuf_pos, priv->rbuf_len);
  74                 priv->rbuf_pos = 0;
  75         }
  76
  77         if (priv->rbuf_len == BUFFER_SIZE)
  78                 return 1;
  79
  80         n = read_wrapper(ip_data, priv->rbuf + priv->rbuf_len, BUFFER_SIZE - priv->rbuf_len);
  81         if (n == -1)
  82                 return -1;
  83         if (n == 0)
  84                 return 0;
  85
  86         priv->rbuf_len += n;
  87         return 1;
  88 }
  89
  90 static inline void buffer_consume(struct input_plugin_data *ip_data, int n)
  91 {
  92         struct aac_private *priv = ip_data->private;
  93
  94         BUG_ON(n > buffer_length(ip_data));
  95
  96         priv->rbuf_pos += n;
  97 }
  98
  99 static int buffer_fill_min(struct input_plugin_data *ip_data, int len)
 100 {
 101         int rc;
 102
 103         BUG_ON(len > BUFFER_SIZE);
 104
 105         while (buffer_length(ip_data) < len) {
 106                 rc = buffer_fill(ip_data);
 107                 if (rc <= 0)
 108                         return rc;
 109         }
 110         return 1;
 111 }
 112
 113 /* 'data' must point to at least 6 bytes of data */
 114 static inline int parse_frame(const unsigned char data[6])
 115 {
 116         int len;
 117
 118         /* http://www.audiocoding.com/modules/wiki/?page=ADTS */
 119
 120         /* first 12 bits must be set */
 121         if (data[0] != 0xFF)
 122                 return 0;
 123         if ((data[1] & 0xF0) != 0xF0)
 124                 return 0;
 125
 126         /* layer is always '00' */
 127         if ((data[1] & 0x06) != 0x00)
 128                 return 0;
 129
 130         /* frame length is stored in 13 bits */
 131         len  = data[3] << 11;   /* ..1100000000000 */
 132         len |= data[4] << 3;    /* ..xx11111111xxx */
 133         len |= data[5] >> 5;    /* ..xxxxxxxxxx111 */
 134         len &= 0x1FFF;          /* 13 bits */
 135         return len;
 136 }
 137
 138 /* scans forward to the next aac frame and makes sure
 139  * the entire frame is in the buffer.
 140  */
 141 static int buffer_fill_frame(struct input_plugin_data *ip_data)
 142 {
 143         unsigned char *data;
 144         int rc, n, len;
 145         int max = 32768;
 146
 147         while (1) {
 148                 /* need at least 6 bytes of data */
 149                 rc = buffer_fill_min(ip_data, 6);
 150                 if (rc <= 0)
 151                         return rc;
 152
 153                 len = buffer_length(ip_data);
 154                 data = buffer_data(ip_data);
 155
 156                 /* scan for a frame */
 157                 for (n = 0; n < len - 5; n++) {
 158                         /* give up after 32KB */
 159                         if (max-- == 0) {
 160                                 d_print("no frame found!\n");
 161                                 /* FIXME: set errno? */
 162                                 return -1;
 163                         }
 164
 165                         /* see if there's a frame at this location */
 166                         rc = parse_frame(data + n);
 167                         if (rc == 0)
 168                                 continue;
 169
 170                         /* found a frame, consume all data up to the frame */
 171                         buffer_consume(ip_data, n);
 172
 173                         /* rc == frame length */
 174                         rc = buffer_fill_min(ip_data, rc);
 175                         if (rc <= 0)
 176                                 return rc;
 177
 178                         return 1;
 179                 }
 180
 181                 /* consume what we used */
 182                 buffer_consume(ip_data, n);
 183         }
 184         /* not reached */
 185 }
 186
 187 static int aac_open(struct input_plugin_data *ip_data)
 188 {
 189         struct aac_private *priv;
 190         faacDecConfigurationPtr neaac_cfg;
 191         int ret, n;
 192
 193         /* init private struct */
 194         priv = xnew0(struct aac_private, 1);
 195         priv->decoder = faacDecOpen();
 196         ip_data->private = priv;
 197
 198         /* set decoder config */
 199         neaac_cfg = faacDecGetCurrentConfiguration(priv->decoder);
 200         neaac_cfg->outputFormat = FAAD_FMT_16BIT;       /* force 16 bit audio */
 201         neaac_cfg->downMatrix = 1;                      /* 5.1 -> stereo */
 202         neaac_cfg->dontUpSampleImplicitSBR = 0;         /* upsample, please! */
 203         faacDecSetConfiguration(priv->decoder, neaac_cfg);
 204
 205         /* find a frame */
 206         if (buffer_fill_frame(ip_data) <= 0) {
 207                 ret = -IP_ERROR_FILE_FORMAT;
 208                 goto out;
 209         }
 210
 211         /* in case of a bug, make sure there is at least some data
 212          * in the buffer for faacDecInit() to work with.
 213          */
 214         if (buffer_fill_min(ip_data, 256) <= 0) {
 215                 d_print("not enough data\n");
 216                 ret = -IP_ERROR_FILE_FORMAT;
 217                 goto out;
 218         }
 219
 220         /* init decoder, returns the length of the header (if any) */
 221         n = faacDecInit(priv->decoder, buffer_data(ip_data), buffer_length(ip_data),
 222                 &priv->sample_rate, &priv->channels);
 223         if (n < 0) {
 224                 d_print("faacDecInit failed\n");
 225                 ret = -IP_ERROR_FILE_FORMAT;
 226                 goto out;
 227         }
 228
 229         /* skip the header */
 230         d_print("skipping header (%d bytes)\n", n);
 231
 232         buffer_consume(ip_data, n);
 233
 234         d_print("sample rate %luhz, channels %u\n", priv->sample_rate, priv->channels);
 235
 236         /*faacDecInitDRM(priv->decoder, priv->sample_rate, priv->channels);*/
 237
 238         ip_data->sf = sf_rate(priv->sample_rate) | sf_channels(priv->channels) | sf_bits(16) | sf_signed(1);
 239 #if defined(WORDS_BIGENDIAN)
 240         ip_data->sf |= sf_bigendian(1);
 241 #endif
 242         return 0;
 243 out:
 244         faacDecClose(priv->decoder);
 245         free(priv);
 246         return ret;
 247 }
 248
 249 static int aac_close(struct input_plugin_data *ip_data)
 250 {
 251         struct aac_private *priv = ip_data->private;
 252
 253         faacDecClose(priv->decoder);
 254         free(priv);
 255         ip_data->private = NULL;
 256         return 0;
 257 }
 258
 259 /* returns -1 on fatal errors
 260  * returns -2 on non-fatal errors
 261  * 0 on eof
 262  * number of bytes put in 'buffer' on success */
 263 static int decode_one_frame(struct input_plugin_data *ip_data, void *buffer, int count)
 264 {
 265         struct aac_private *priv = ip_data->private;
 266         unsigned char *aac_data;
 267         unsigned int aac_data_size;
 268         faacDecFrameInfo frame_info;
 269         char *sample_buf;
 270         int bytes, rc;
 271
 272         rc = buffer_fill_frame(ip_data);
 273         if (rc <= 0)
 274                 return rc;
 275
 276         aac_data = buffer_data(ip_data);
 277         aac_data_size = buffer_length(ip_data);
 278
 279         /* aac data -> raw pcm */
 280         sample_buf = faacDecDecode(priv->decoder, &frame_info, aac_data, aac_data_size);
 281
 282         buffer_consume(ip_data, frame_info.bytesconsumed);
 283
 284         if (!sample_buf || frame_info.bytesconsumed <= 0) {
 285                 d_print("fatal error: %s\n", faacDecGetErrorMessage(frame_info.error));
 286                 errno = EINVAL;
 287                 return -1;
 288         }
 289
 290         if (frame_info.error != 0) {
 291                 d_print("frame error: %s\n", faacDecGetErrorMessage(frame_info.error));
 292                 return -2;
 293         }
 294
 295         if (frame_info.samples <= 0)
 296                 return -2;
 297
 298         if (frame_info.channels != priv->channels || frame_info.samplerate != priv->sample_rate) {
 299                 d_print("invalid channel or sample_rate count\n");
 300                 return -2;
 301         }
 302
 303         /* 16-bit samples */
 304         bytes = frame_info.samples * 2;
 305
 306         if (bytes > count) {
 307                 /* decoded too much, keep overflow */
 308                 priv->overflow_buf = sample_buf + count;
 309                 priv->overflow_buf_len = bytes - count;
 310                 memcpy(buffer, sample_buf, count);
 311                 return count;
 312         } else {
 313                 memcpy(buffer, sample_buf, bytes);
 314         }
 315         return bytes;
 316 }
 317
 318 static int aac_read(struct input_plugin_data *ip_data, char *buffer, int count)
 319 {
 320         struct aac_private *priv = ip_data->private;
 321         int rc;
 322
 323         /* use overflow from previous call (if any) */
 324         if (priv->overflow_buf_len) {
 325                 int len = priv->overflow_buf_len;
 326
 327                 if (len > count)
 328                         len = count;
 329
 330                 memcpy(buffer, priv->overflow_buf, len);
 331                 priv->overflow_buf += len;
 332                 priv->overflow_buf_len -= len;
 333                 return len;
 334         }
 335
 336         do {
 337                 rc = decode_one_frame(ip_data, buffer, count);
 338         } while (rc == -2);
 339         return rc;
 340 }
 341
 342 static int aac_seek(struct input_plugin_data *ip_data, double offset)
 343 {
 344         return -IP_ERROR_FUNCTION_NOT_SUPPORTED;
 345 }
 346
 347 /* copied from mad.c */
 348 static void get_comment(struct keyval *c, int *iptr, ID3 *id3, enum id3_key key, const char *key_name)
 349 {
 350         int i = *iptr;
 351
 352         c[i].val = id3_get_comment(id3, key);
 353         if (c[i].val == NULL)
 354                 return;
 355         c[i].key = xstrdup(key_name);
 356         *iptr = i + 1;
 357 }
 358
 359 /* based on read_comments from mad.c */
 360 static int aac_read_comments(struct input_plugin_data *ip_data,
 361                 struct keyval **comments)
 362 {
 363         struct ID3 *id3;
 364         int rc, fd, i;
 365
 366         fd = open(ip_data->filename, O_RDONLY);
 367         if (fd == -1)
 368                 return -1;
 369
 370         id3 = id3_new();
 371
 372         rc = id3_read_tags(id3, fd, ID3_V1 | ID3_V2);
 373         if (rc == -1) {
 374                 d_print("error: %s\n", strerror(errno));
 375                 *comments = xnew0(struct keyval, 1);
 376                 goto out;
 377         }
 378
 379         *comments = xnew0(struct keyval, NUM_ID3_KEYS + 1);
 380         i = 0;
 381         get_comment(*comments, &i, id3, ID3_ARTIST, "artist");
 382         get_comment(*comments, &i, id3, ID3_ALBUM, "album");
 383         get_comment(*comments, &i, id3, ID3_TITLE, "title");
 384         get_comment(*comments, &i, id3, ID3_DATE, "date");
 385         get_comment(*comments, &i, id3, ID3_GENRE, "genre");
 386         get_comment(*comments, &i, id3, ID3_DISC, "discnumber");
 387         get_comment(*comments, &i, id3, ID3_TRACK, "tracknumber");
 388         get_comment(*comments, &i, id3, ID3_ALBUMARTIST, "albumartist");
 389 out:
 390         close(fd);
 391         id3_free(id3);
 392         return 0;
 393 }
 394
 395 static int aac_duration(struct input_plugin_data *ip_data)
 396 {
 397         struct aac_private *priv = ip_data->private;
 398         faacDecFrameInfo frame_info;
 399         int samples = 0, bytes = 0, frames = 0;
 400         off_t file_size;
 401         char *sample_buf;
 402
 403         file_size = lseek(ip_data->fd, 0, SEEK_END);
 404         if (file_size == -1)
 405                 return -IP_ERROR_FUNCTION_NOT_SUPPORTED;
 406
 407         /* guess track length by decoding the first 10 frames */
 408         while (frames < 10) {
 409                 if (buffer_fill_frame(ip_data) <= 0)
 410                         break;
 411
 412                 sample_buf = faacDecDecode(priv->decoder, &frame_info,
 413                         buffer_data(ip_data), buffer_length(ip_data));
 414                 if (frame_info.error == 0 && frame_info.samples > 0) {
 415                         samples += frame_info.samples;
 416                         bytes += frame_info.bytesconsumed;
 417                         frames++;
 418                 }
 419                 if (frame_info.bytesconsumed == 0)
 420                         break;
 421
 422                 buffer_consume(ip_data, frame_info.bytesconsumed);
 423         }
 424
 425         if (frames == 0)
 426                 return -IP_ERROR_FUNCTION_NOT_SUPPORTED;
 427
 428         samples /= frames;
 429         samples /= priv->channels;
 430         bytes /= frames;
 431
 432         return ((file_size / bytes) * samples) / priv->sample_rate;
 433 }
 434
 435 const struct input_plugin_ops ip_ops = {
 436         .open = aac_open,
 437         .close = aac_close,
 438         .read = aac_read,
 439         .seek = aac_seek,
 440         .read_comments = aac_read_comments,
 441         .duration = aac_duration
 442 };
 443
 444 const char * const ip_extensions[] = { "aac", NULL };
 445 const char * const ip_mime_types[] = { "audio/aac", "audio/aacp", NULL };